A Rare Presentation of Plexiform Schwannoma of the Thumb.

Plexiform schwannomas are rare, benign, neural crest-derived tumors that commonly occur in the hand and upper extremities. They may be sporadic or associated with neurofibromatosis type 2. Although previous literature has described plexiform schwannomas occurring in fingers, nerve and tendon sheaths, and intraosseous lesions, this is the first known case of a plexiform schwannoma of the thumb. This is a case of a growing, painless, subungual mass of the thumb in a 54-year-old patient. After surgical excision and subsequent immunohistochemical examination, the patient was diagnosed with a plexiform schwannoma. This highlights the importance of maintenance a broad differential before surgery and obtaining a proper diagnosis using histopathology.